Review of current trends in enhancing bioavailability of poorly water soluble drugs by liposomal interventions

One of the several ways of enhancing the solubility of poorly soluble drugs is liposomes formulations. Research on liposomes formulations has progressed from that of conventional vesicles to new generation liposomes, such as cationic liposomes, temperature sensitive liposomes, and virosomes, by modulating the formulation techniques and lipid composition. Thermosensitive liposomes are also a promising tool for external targeting of drugs to solid tumors when used in combination with local hyperthermia or high intensity focused ultrasound. In vivo results have demonstrated strong evidence that external targeting is superior over passive targeting achieved by highly stable long-circulating drug formulations like PEGylated liposomal doxorubicin. This review is to compare the therapeutic effect of current clinically approved liposomebased drugs with free drugs and summarize the historical development and effects of particular phospholipids and surfactants on the biophysical properties and in vivo efficacy of thermosensitive liposome formulations. Drug delivery guided by magnetic resonance imaging is also discussed. The combination of external targeting with thermosensitive liposomes and magnetic resonance-guided drug delivery will be the unique characteristics of this nanotechnology approach in medicine.